<!DOCTYPE html>
<html>

<head>
	<meta charset="UTF-8">
	<title>Bootstrap 实例</title>

	<link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" integrity="sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M"
	 crossorigin="anonymous">

</head>

<body style="height:500px">
	<nav class="navbar navbar-expand-sm bg-dark navbar-dark fixed-top">
		<a class="navbar-brand" href="#">Logo</a>
		<ul class="navbar-nav">
			<li class="nav-item">
				<a class="nav-link" href="#">Link</a>
			</li>
			<li class="nav-item">
				<a class="nav-link" href="#">Link</a>
			</li>
		</ul>
	</nav>

	<div class="container-fluid" style="margin-top:80px">
		<h3>固定导航栏</h3>
		<p>导航栏可以固定在头部或者底部。</p>
		<h1>滚动页面查看效果。</h1>
	</div>
</body>

</html>